Endocrinology — MCQs

Endocrinology Indian Medical PG Practice Questions and MCQs

Question 1521: A patient with a known history of type 1 diabetes presents with confusion and sweating. The blood glucose level is 50 mg/dL. What is the most appropriate first action?

A. Administer an oral carbohydrate (Correct Answer)
B. Give a subcutaneous insulin injection
C. Administer intravenous glucagon
D. Provide a high-protein snack

Explanation: **Administer an oral carbohydrate** - The patient presents with symptoms of **hypoglycemia** (confusion, sweating) and a **blood glucose level of 50 mg/dL**, which is below the normal range, indicating an urgent need for glucose [1]. - An **oral carbohydrate** (e.g., glucose tablets, juice, or sugary drinks) is the fastest and most appropriate first action for conscious patients with mild to moderate hypoglycemia. *Give a subcutaneous insulin injection* - **Insulin** lowers blood glucose levels and would worsen the patient's current hypoglycemic state, potentially leading to severe complications. - Insulin is indicated for hyperglycemia, not for hypoglycemia. *Administer intravenous glucagon* - **Intravenous glucagon** is used for severe hypoglycemia, particularly in unconscious patients or when oral intake is not possible. - While effective, administering an oral carbohydrate is preferred and safer for a conscious patient. *Provide a high-protein snack* - A **high-protein snack** is not the best immediate treatment for acute hypoglycemia because proteins are digested slower and do not raise blood glucose as quickly as simple carbohydrates. - A combination of carbohydrates and protein might be offered after the immediate hypoglycemic episode has been resolved with fast-acting carbohydrates to help stabilize blood glucose.

Question 1522: A 38-year-old woman presents with visual field defects and galactorrhea. An MRI reveals a pituitary mass. Which class of drugs would be most appropriate for treating this condition?

A. Dopamine agonist (Correct Answer)
B. Beta-blocker
C. Serotonin antagonist
D. Acetylcholinesterase inhibitor

Explanation: ***Dopamine agonist*** - **Galactorrhea** suggests hyperprolactinemia, often caused by a **prolactinoma** [3] (a type of pituitary adenoma), which can be effectively treated with dopamine agonists [1]. - Dopamine agonists (e.g., **bromocriptine, cabergoline**) mimic dopamine's inhibitory effect on prolactin secretion, leading to a reduction in prolactin levels and tumor shrinkage, thus resolving visual field defects [1],[2]. *Beta-blocker* - **Beta-blockers** are primarily used to treat conditions like hypertension, angina, and anxiety, and do not directly address pituitary tumors or hyperprolactinemia. - They work by blocking the effects of adrenaline and do not influence prolactin secretion or tumor size. *Serotonin antagonist* - **Serotonin antagonists** are used in various conditions, including migraine prophylaxis and treatment of carcinoid syndrome, but they have no role in managing pituitary masses or high prolactin levels. - These drugs target serotonin receptors and do not affect dopamine pathways relevant to prolactin regulation. *Acetylcholinesterase inhibitor* - **Acetylcholinesterase inhibitors** are used to treat conditions like Alzheimer's disease and myasthenia gravis by increasing acetylcholine levels in the brain. - They are not indicated for the treatment of pituitary tumors or hyperprolactinemia, as their mechanism of action is unrelated to prolactin regulation.

Question 1523: A 28-year-old female presents with panic attacks, palpitations, sweating, and chest pain. EKG shows sinus tachycardia. Labs reveal decreased TSH and increased FT4. Analyze and choose the most likely diagnosis.

A. GAD
B. Panic Disorder
C. Hyperthyroidism (Correct Answer)
D. Mitral valve prolapse

Explanation: ***Hyperthyroidism*** - The combination of **panic attacks**, **palpitations**, **sweating**, and **chest pain** are classic symptoms of **hyperthyroidism**, often mimicking anxiety [1]. - The lab results of **decreased TSH** and **increased free T4 (FT4)** are definitive for hyperthyroidism, indicating an overactive thyroid gland [2]. *GAD* - While **Generalized Anxiety Disorder (GAD)** can present with anxiety, palpitations, and sweating, it would not explain the **abnormal thyroid function tests**. - GAD is a diagnosis of exclusion in the presence of an underlying medical condition causing anxiety-like symptoms. *Panic Disorder* - **Panic disorder** is characterized by recurrent, unexpected panic attacks with physical symptoms like palpitations and chest pain. - However, **panic disorder** would not account for the **decreased TSH** and **increased FT4** found in the lab results. *Mitral valve prolapse* - **Mitral valve prolapse** can cause **palpitations** and sometimes atypical chest pain but does not typically cause the widespread symptoms of panic attacks or sweating. - It would not lead to **abnormal thyroid hormone levels** seen in the lab findings.

Question 1524: A 45-year-old female presents with weight gain, muscle weakness, and easy bruising. Laboratory tests show elevated cortisol levels. What is the most likely diagnosis?

A. Addison's disease
B. Hypothyroidism
C. Cushing's syndrome (Correct Answer)
D. Pheochromocytoma

Explanation: ***Cushing's syndrome*** - **Weight gain**, **muscle weakness**, and **easy bruising** are classic signs of Cushing's syndrome [2], caused by prolonged exposure to high levels of cortisol. - **Elevated cortisol levels** confirmed by laboratory tests are diagnostic for Cushing's syndrome [1]. *Addison's disease* - This condition is characterized by **adrenal insufficiency**, leading to *low* cortisol levels, not elevated ones. - Clinical features often include **hyperpigmentation**, fatigue, weight loss, and hypotension, which are contrary to the symptoms described. *Hypothyroidism* - Although **weight gain** and **fatigue** can be symptoms, muscle weakness to the degree causing easy bruising is less typical. - It involves low thyroid hormone levels, not elevated cortisol. *Pheochromocytoma* - This is a tumor of the adrenal medulla that secretes **catecholamines**, leading to symptoms like episodes of hypertension, palpitations, and sweating. - It does not primarily cause elevated cortisol levels or the specific constellation of symptoms described.

Question 1525: A 30-year-old female with Graves' disease presents with worsening eye symptoms, including double vision and proptosis. What is the underlying mechanism of her eye symptoms?

A. Excess thyroid hormone production
B. Inflammation of the optic nerve
C. Autoimmune-mediated inflammation of extraocular muscles (Correct Answer)
D. Increased intraocular pressure

Explanation: ***Autoimmune-mediated inflammation of extraocular muscles*** - **Graves' ophthalmopathy** is characterized by an autoimmune response, where **antibodies** mistakenly target receptors on fibrocytes in the **extraocular muscles** and periorbital tissues [1], [2]. - This leads to **inflammation**, swelling, and accumulation of **glycosaminoglycans**, causing muscle enlargement, **proptosis**, and restricted eye movement (leading to diplopia) [2], [3]. *Excess thyroid hormone production* - While **Graves' disease** is characterized by **excess thyroid hormone**, the eye symptoms (**Graves' ophthalmopathy**) are a separate, though often co-occurring, autoimmune process [1]. - The severity of ophthalmopathy does not always correlate with the level of **thyroid hormone** [1]. *Inflammation of the optic nerve* - **Optic neuritis** can occur with other autoimmune diseases (e.g., multiple sclerosis) but is not the primary mechanism behind the common eye symptoms of **Graves' ophthalmopathy** like proptosis and double vision. - While severe proptosis can indirectly lead to **optic neuropathy** due to compression, it's a secondary complication, not the initial cause of the orbital symptoms [3]. *Increased intraocular pressure* - **Increased intraocular pressure** typically causes **glaucoma** and primarily affects the optic nerve's structure and function, leading to visual field defects. - It does not directly cause the **proptosis** or the **restrictive extraocular myopathy** that leads to diplopia seen in **Graves' ophthalmopathy**.

Question 1526: A 65-year-old woman with a history of hyperthyroidism presents with fever, tachycardia, and confusion. What is the most likely diagnosis?

A. Thyroid storm (Correct Answer)
B. Myxedema coma
C. Sepsis
D. Pheochromocytoma

Explanation: ***Thyroid storm*** - **Thyroid storm** is a life-threatening exacerbation of hyperthyroidism characterized by symptoms such as **fever**, **tachycardia**, and altered mental status like **confusion** [1]. - The patient's history of **hyperthyroidism** makes this diagnosis highly probable in the context of these severe symptoms [1]. *Myxedema coma* - **Myxedema coma** is the extreme manifestation of **hypothyroidism**, not hyperthyroidism, and would present with symptoms such as **hypothermia**, **bradycardia**, and severe lethargy, which contradict the patient's presentation. - The patient's history of **hyperthyroidism** also makes myxedema coma an unlikely diagnosis. *Sepsis* - While **fever**, **tachycardia**, and **confusion** can be seen in sepsis, the underlying history of **hyperthyroidism** and the acute, severe presentation points more specifically to thyroid storm [1]. - Sepsis would typically have a clear infectious source, which is not mentioned in this scenario, and would not solely account for the severe systemic hypermetabolic state described. *Pheochromocytoma* - **Pheochromocytoma** is a tumor that typically presents with paroxysmal episodes of **hypertension**, **palpitations**, and **sweating** due to excessive catecholamine release. - Although it can cause **tachycardia**, the symptom complex including **fever** and a history of hyperthyroidism makes it less likely than a thyroid storm.

Question 1527: A 45-year-old woman presents with fatigue, dry skin, and constipation. Physical examination reveals a delayed relaxation phase of deep tendon reflexes. Laboratory tests show elevated TSH and low free T4. What is the most likely diagnosis?

A. Hyperthyroidism
B. Subclinical hypothyroidism
C. Primary hypothyroidism (Correct Answer)
D. Thyroiditis

Explanation: ***Primary hypothyroidism*** - The constellation of **fatigue, dry skin, constipation**, and a **delayed relaxation phase of deep tendon reflexes** are classic symptoms of hypothyroidism [1]. - **Elevated TSH** and **low free T4** confirm primary hypothyroidism, indicating the thyroid gland itself is underactive [1]. *Hyperthyroidism* - This condition presents with symptoms opposite to those described, such as **weight loss, heat intolerance, diarrhea**, and **tachycardia** [1]. - Laboratory findings would typically show **low TSH** and **elevated free T4** or free T3 [1]. *Subclinical hypothyroidism* - Characterized by an **elevated TSH** but **normal free T4** levels; patients may be asymptomatic or have mild symptoms. - The patient's **low free T4** explicitly rules out subclinical hypothyroidism. *Thyroiditis* - Though thyroiditis can cause hypothyroidism (e.g., Hashimoto's thyroiditis), the term itself refers to inflammation of the thyroid. - While it's a potential cause, **primary hypothyroidism** is the most direct diagnostic classification based on the presented symptoms and lab results.

Question 1528: A 45-year-old male with bipolar disorder who is well-controlled on lithium develops hypothyroidism. What is the most appropriate management?

A. Discontinue lithium
B. Add levothyroxine (Correct Answer)
C. Switch to valproate
D. Reduce lithium dose

Explanation: ***Add levothyroxine*** - Hypothyroidism is a known side effect of lithium therapy, but it can be effectively managed by adding **levothyroxine** while continuing lithium [1]. This allows the patient to maintain the benefits of lithium for bipolar disorder control. - The goal is to treat the hypothyroidism, not necessarily to stop the effective psychiatric treatment, especially when the bipolar disorder is **well-controlled**. *Discontinue lithium* - Discontinuing lithium would likely lead to a **relapse of bipolar disorder**, as the patient is described as "well-controlled" on the medication. - While lithium is the cause of hypothyroidism in this scenario, simply stopping it is not the most appropriate first-line management when the hypothyroidism is treatable. *Switch to valproate* - Switching to valproate may destabilize the patient's bipolar disorder, especially since they are currently **well-controlled on lithium**. - Valproate also has its own side effect profile and may not be as effective for all patients with bipolar disorder. *Reduce lithium dose* - Reducing the lithium dose might alleviate the hypothyroidism slightly, but it could **compromise the therapeutic efficacy** of lithium for bipolar disorder. - If hypothyroidism develops, the primary approach is to treat the thyroid dysfunction directly rather than risk bipolar symptom recurrence [1].

Question 1529: What are the endocrine and autoimmune mechanisms involved in a 55-year-old female presenting with palpitations, tremors, weight loss, high free T4, and low TSH?

A. Graves' disease leading to hyperthyroidism due to autoimmune stimulation of the thyroid. (Correct Answer)
B. Hashimoto's thyroiditis causing autoimmune destruction of the thyroid and resulting in hypothyroidism.
C. Adrenal insufficiency resulting in decreased cortisol and aldosterone levels.
D. Primary hyperparathyroidism leading to increased calcium and PTH secretion.

Explanation: ***Graves' disease leading to hyperthyroidism due to autoimmune stimulation of the thyroid.*** - The presented symptoms of **palpitations, tremors, and weight loss** are classic signs of **hyperthyroidism** [1, 2]. The lab results of **high free T4** and **low TSH** confirm this state [2]. - **Graves' disease** is an **autoimmune condition** where antibodies (specifically **thyroid-stimulating immunoglobulins**) bind to the TSH receptors on thyroid follicular cells, stimulating excessive thyroid hormone production [1, 2]. *Hashimoto's thyroiditis causing autoimmune destruction of the thyroid and resulting in hypothyroidism.* - **Hashimoto's thyroiditis** is an autoimmune disease that typically leads to **hypothyroidism** due to the gradual destruction of the thyroid gland. - This condition is characterized by **low free T4** and **high TSH**, symptoms like **fatigue and weight gain**, which are opposite to the patient's presentation. *Adrenal insufficiency resulting in decreased cortisol and aldosterone levels.* - **Adrenal insufficiency** (e.g., Addison's disease) involves a deficiency of adrenal hormones, primarily **cortisol** and **aldosterone**. - Symptoms typically include **fatigue, weight loss (often due to anorexia), hypotension, and hyperpigmentation**, but not the classic hypermetabolic symptoms like palpitations and tremors, nor the specific thyroid lab derangements. *Primary hyperparathyroidism leading to increased calcium and PTH secretion.* - **Primary hyperparathyroidism** is characterized by excessive parathyroid hormone (PTH) secretion, leading to **hypercalcemia**. - Symptoms are often non-specific but may include **fatigue, bone pain, kidney stones, and psychiatric symptoms**, and does not explain the high free T4 and low TSH or the specific hyperthyroid symptoms presented.

Question 1530: What is the primary pathophysiological consequence of Graves' disease?

A. Results in hypothyroidism
B. Equally common in both sexes
C. Results in hyperthyroidism (Correct Answer)
D. Common in Male

Explanation: Graves' disease is an **autoimmune disorder** where antibodies stimulate the **TSH receptor**, leading to excessive thyroid hormone production [1], [2]. This overproduction of T3 and T4 results in a **hypermetabolic state** characteristic of hyperthyroidism [2]. Graves' disease is significantly more common in **females** than in males, with a female-to-male ratio as high as 5-10:1 [1], [2]. This gender predisposition is consistent with many other **autoimmune diseases**.

Practice by Chapter

Diabetes Mellitus

Practice Questions

Thyroid Disorders

Practice Questions

Adrenal Gland Disorders

Practice Questions

Pituitary Disorders

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Calcium and Bone Metabolism

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Reproductive Endocrinology

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Lipid Disorders

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Endocrine Hypertension

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Multiple Endocrine Neoplasia

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Obesity and Metabolic Syndrome

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Neuroendocrine Tumors

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Endocrine Emergencies

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